As a multilayer electronic component which is of interest to the present invention, for example, there is known an electronic component which is integrally formed from a plurality of electronic elements, such as a semiconductor element and a chip element, and which has the structure in which these electronic elements are mounted on a major surface of a ceramic substrate, and in which the electronic elements are buried in a resin layer formed on the major surface of the ceramic substrate (for example, see Patent Document 1).
When a particular electronic device is formed using a multilayer electronic component having the structure as described above, the multilayer electronic component is mounted on a mounting substrate which is to be used as a mother board. The multilayer electronic component has pad electrodes for external connection, which are generally formed on an outside-facing major surface of a resin layer of the multilayer electronic component, and when the pad electrodes are connected to conductive lands formed on the mounting substrate by soldering, a mounting state is obtained. The above pad electrodes are electrically connected to respective wiring conductors provided at a ceramic substrate side via conductors (i.e., columnar conductors) disposed in the resin layer.
In addition, reduction in size and height has been always required of an electronic device having the multilayer electronic component as described above. As described above, when the structure in which the multilayer electronic component is mounted on the mounting substrate is carefully observed, even the thickness of a solder provided between the pad electrode at the multilayer electronic component side and the conductive land at the mounting substrate side interferes with the reduction in size and height, and when the reduction in size and height is further pursued, the reduction in thickness of the solder also becomes an important subject. Furthermore, it may also be construed that even the thickness of the pad electrode and that of the conductive land also interfere with the reduction in size and height.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2003-124435